1. Field of the Invention
The present invention relates generally to a thin-walled rectilinear motion rolling guide unit and relates more particularly to said guide unit equipped with stress-resisting ball retainer capable of being miniaturized as a whole, thereby insuring high accuracy and long durability of a rectilinearly reciprocating movement of the guide unit.
2. Description of the Prior Art
A stress-resisting ball retainer was generally employed in telescoping ball bearing slides including conventional rack means and mating pinions such as, for example, in the invention of U.S. Pat. No. 3,857,618 specification.
As clearly illustrated in the specification and particularly in FIG. 1 of the said U.S. patent, the pinion shafts are disposed in parallel to the upper surfaces of telescoping ball bearing slides.
In the prior art invention, when radial load is applied to said slide unit, vertical displacement takes place in the telescoping slides, thereby influencing the meshing condition between the rack members and the pinions such that the rotational friction of the pinions are increased. For this reason, telescoping slides of the U.S. patent can find only a limited application due to a rather poor performance as rectilinear reciprocating motion rolling units such as, for example, telescoping slide members exclusively used for a cabinet drawers and a cabinet desk.
Further, FIG. 10 of the above-mentioned U.S. patent illustrates a technology wherein to prevent the meshing conditions during operation, varying between rack means and pinion means due to vertical displacement of the overlying table means, the surface of the table is positioned vertical to the axis of the pinion but, in this case, the rotational axis of the pinion must be supported on an intermediate member corresponding to the ball retainer of FIG. 1, therefore a substantial mechanical strength as well as complicated configuration is required for the fabrication of the intermediate member, resulting in a higher production cost.
Moreover, the unit disclosed by the U.S. patent has no driving means installed in itself so that separate driving means for moving the slide members was required.